This chapter considers the reception of Mahler by Schoenberg, Berg, and Webern, with particular attention to parallel threads of interpretation. On one hand, the triumvirate championed their idol with determination and perseverance, to make a place for him in the centuries-long progression of Western compositional history and to establish as the culmination of this history (at least provisionally) their own works, with Schoenberg’s twelve-tone method as its most advanced expression. But another, backward-looking Second Viennese interpretation of Mahler’s music existed from the beginning: as the last manifestation of a musical paradise eternally closed to subsequent composers, who, unlike Mahler, rejected the commandment to leave tonality intact. As self-styled heirs, then, the Second Viennese School faced an irresolvable dilemma: their succession through an initially “atonal” and then dodecaphonic language required the destruction of this paradise, which existed on a tonal foundation.